1. Field of the Invention
This invention relates to radar antennas, and more particularly to integrated primary and secondary radar antennas.
2. Description of the Prior Art
Primary radar antennas and secondary radar antennas or identification-friend-foe (IFF) can be designed to be structurally separate, for example in the form of a pillbox antenna and an IFF bar antenna, and can then be combined spatially one above the other. A bar antenna with a series-fed radar antenna and an integrated IFF bar antenna are also known in the art. The disadvantage of the series-fed radar antenna, for example, a wave guide slot antenna, is in its narrow band characteristic and, in particular, in the frequency dependency of the direction of maximum radiation.